1. Field of the Invention
The field of this invention relates to an improvement to an attachment to the upper end of a ladder for stabilizing the ladder relative to a substantially vertical surface.
2. Description of the Prior Art
A ladder is commonly used to help people reach places they would not ordinarily reach. Ladders are often used to climb onto roofs of building and are used when washing windows or painting. In normal use, the bottom portion of the ladder rests on the ground or other similar horizontal surface and the upper end of the ladder typically leans against the vertical wall surface of a building or work surface. The ladder is oriented at an angle which makes it easy for a user to climb up and down the ladder and also aids in keeping the ladder from slipping.
The use of ladders in the United States is known to be a major cause of accidents each and every year. One problem with ladders is that there is lateral instability because the upper end of the ladder rests on the vertical surface with only the small width of the ladder defining the contact area with the vertical surface. When a person on the ladder and located at or near the upper ends extends laterally from the ladder when painting, cleaning or doing other type of work, the upper end of the ladder may be caused to slide along the vertical surface. This can cause the ladder and the person to fall to the horizontal supporting surface. Generally such falls cause injury to the person.
One of the problems with ladders is that their width is very narrow compared to their length which significantly increases the probability of lateral instability. Accordingly, it would be highly desirable to have a ladder that has a large lateral dimension in order to improve this lateral stability. However, significantly increasing the width of the ladder over its entire longitudinal length is not generally feasible since such increase in width will substantially increase not only the cost of manufacture but also decrease its portability by not facilitating being carried by a truck or other type of vehicle to the location of usage.
In order to increase the safety of operation of ladders, it has been common in the past to mount a ladder attachment to the upper end of the ladder. Typically such a ladder attachment is mounted on the uppermost rungs of the ladder and generally has a U-shaped configuration terminating in a pair of foot pad sections. The overall width between the foot pad sections is generally three to four times the width of the ladder. One foot pad section is laterally disposed a distance from one side edge of the ladder with the other foot pad section being disposed the same lateral distance from the opposite side of the ladder.
Generally these foot pad sections frictionally engage the wall surface and because of the increased lateral width, provide increased stability to the ladder minimizing the possibility of the ladder sliding on the vertical surface which can cause the person thereon to fall to the horizontal supporting surface. In the past these ladder attachments have been a significant improvement in the safety of ladders. However, these ladder attachments are not fail-safe and the upper end of the ladder can still slide on the vertical wall surface. Frequently this sliding is caused by the user himself who now feels the increased stability and therefore reaches even further laterally than one should until a sufficient imbalance is obtained and the ladder and the attachment both begin to slide.
Such ladder attachments in the past have not been designed to be adjustable. Adjustability is desired so the attachment will be usable in confined areas and also expandable to increased width in open areas. Also, adjustability is desired so the attachment will connect with different types of ladders. Also, it is desirable to lock the attachment to the ladder to prevent the attachment from falling free of the ladder during the time the ladder is moved. Such locking devices in the past have been quite complex requiring a lengthy installing procedure and have been expensive to manufacture, hence expensive to purchase by the user.